Voltage regulator



Patented June 22, 1926.

UNITED STATES 1,589,810 PATENT OFFICE.

HARRY B. MARSHALL, OF ST. LOUIS, MISSOURI; EDWARD W. TERRY, ADMINISTRATOR OF SAID MARSHALL, ASSIGNOR TO MARSHALL ELECTRIC COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

VOLTAGE REGULATOR.

Application led June 13, 1824. Serial No. 718,880.

'My invention relates to rheost-ats in which the resistance is varied by varying the compression of a resistance, and to electric regulating or controlling devices in which the resistanee-alteringr compression is varied automatically in response to Variations in the currentI flowing' through a certain circuit.

In some, ot' its general aspects, my invention aims to provide a compact, inexpensive, easily adjusted and highly effective automatic regulator for varyingl the resistance in response to the llovv o't current through a certain eireuit. For this general purpose7 in v invention provides resistance compression means consisting' oi a magnetically a0- lliateil rocking member and a thrust meinber operai ively interposed between the rocking member and.-one end of the resistance. and both extending' ohliquely to the axis of eompression of the resistance. It also provides simple and effective means for adjustine; vthe regulator as a whole, tor carrying currentto the. ends` ot the resistance and suitably insulating the resistance from other parts ot the n'ieehanism, provides simple and easily adjusted meansI 'for pivoting the roekimr uien'il'im' upon its support, provides a disposition oi the thrust member' which will make the resultingv variations in the cour' pression of the resistance responsive to relatively small movements of the rocking member. lvloreover. in v invention provides simple (,lertro-niagueiie means ior moving the roelv'inpY member. and provides a construetion in ivnieh a series ot iron parts are dis posed for allordiirer a magnetic circuit through the actuating magnet coil.

Furiherinore. my invention provides an adjustable resistance or regulator of this general class in which the rocking member is .substantially balanced so as to he highly sensitive, in which one of a pair of cooperating solenoid and core members is earried by the rocking member, in which the attraction ot the core or the solenoid is resisted bv a spring'. in which the effective aetion oi'this springr can readily be adjusted with a hiilli degree of accuracy and maintained at any point ot adjustment, and in which the entire mechanism can readily be assembled to aiiord an exceedingly compact unit;

ilore partieulariy, my invention provides;

a rheostat or re lator of this general class in which the roc ing,r member includes apair oi' pivotal arms, provides cooperating pivot elements on these arms and on a stationary part of the appliance, and provides simple means for spacing these arms from each other so as to secure the desired highly sensitive pivotal engagement. It also provides a pivoting arrangement of this general class in which certain of the pivot elements are carried by the casing of the resistance and provides an exceedingly simple arrangement ot the arts for facilitating the assemblyl and adJustment of the nterengaging pivot portions. It also provides simple and effective means for making the necessary circuit connections to both ends of the oompressible resistance. Still further and also more detailed objects will appear from the following' specification and from the aecompanying drawings, in which Fig. 1 is a diagrammatic: view'showing some of the underlying features of my invention.

FigJQ is a perspective view of an embodiment of my invention, with the forward pivot arm of the rocking member out away so as to show the position of the thrust member and of the lower thrust bearing.

Fig. 3 is an enlarged vertical section taken through Fig. 2 along' the axis of the magnet coil and of the compressible resistance.A

Fig. l is a vertical section taken transversely of Fig. 8 along the line of that ligure.

Fig, 5 a perspective View of the main part of the rocking member of the embodiments of Figs. 2, 3 and 4.

Fig. 6 is an enlarged and fragmentary section taken transversely of Fig. 3 through the axis of the eompressible resistance to show the mountingu oi the two cooperating pairs of pivot elements which are. respecn tively carried by the rocking member and the easing o t' the resistance.

Fig. 7 is a diagrammatic lview showing the eil'eetive angular relations of the resistance. thrust member andv rocking member in two positions of the latter.

Fig. S is a diagram of anotherl embodiment ot my invention. namely one in which the pivotal support tor the rocking member is integral 1with the head against which the resistance is compressed, and in which the solenoid and core extend transversely of the thrust member.

In accomplishing some of the purposes of my invention, I employ a compressible resistance, such as the carbon pile R shown in the diagram of Fig. 1, and resist the bodily movement of this resistance in one vdirection by a support S against which the stationary end ot' the resistance bears.v Then I vary the compressionl of this resistance by suitably moving a thrust member T which is arranged for pressing the free end of the resistance towards the said support S. 'Io move this thrust member, I interpose itf-between a presser head 5 which bearsagainst the free end of the resistance (and whicheiectively forms the movable end of the compressible resistance member) and a part of a lever L which forms the rocking member of my appliance. For this purpose, the rocking. member has a thrust portion engaging one end of the thrust member T and disposed at one vside of the axis of compression A of the resistance, the rocking member being pivoted on a ivot axis intersecting this compression axis etween the stationary end of the resistance and the thrust member, thereby caus` in the thrust member to extend at a highly ob ique angle to this axis of compression.

Mounted on the rocking member L is an iron core vC which extends into a solenoid or magnet core M, thereby causing the rocking member to be moved in a direction which is clockwise in Fig. 1 when the current is fiowing through the solenoid coil M. To resist such a movement of the rocking member, I interpose an adjustable spring A be-v tween the rocking member and the support, this spring being here shown as adjustable by means of a screw B. I also desirably forni a weight IV upon the rocking member to counterbalance the weight of the core C, so that the rocking member can be sensitively balanced.

with the parts thus arranged. it will be obvious from Fig. 1 that a movement ot' the rocking member in a clockwise direction will tend to swing the thrust member 'I more nearly into alineinent with the axis of com pression of the resistance (which axis is in a common plane with the pivot ol the rocking member and the upper end ol' the thrust member) thereby reducin, r the distance between the upper or stationary end of the resistance and the lower end of the thrust member so as to increase the compression of the resistance, while a swinging in the opposite direction will decrease the oblique angle between the thrust member and the axis of compression and will reduce the .:ompressing of tliejresistance. It will also be evident that by moving the screw V, I can readily adjust the appliance so as to vary the current flow required in the solenoid for ctieeting a given movement of the. rocking member. l

Referring now to the vembodiment of Figs. 2 to 6 inclusive, this includes as the supporting member of the appliance a bracket desirably formed ot tlat iron and comprising a horizontal top portion 1, a downwardly directed rear flange 2 and a downwardly di- -rected end flange 3, the rear flange Z being -provided with threaded perforations 4 for receiving screws wherebythe bracket may be fastened to any suitable support. Abutting against the lower face of the top 1 of this supporting member is the closed upper end of a casing 5 which houses the compressible resistance, the latter being here shown as consisting of a pile of carbon disks 6 which are insulated 'from the metal casing 5 by an insulating lining 7. The casing 5 is supported from the top 1 by a terminal bolt 8 which is insulated from the said top by an insulating bushing 9 and supported by an outer nut 10.

The top 1 also has depending from it a spool 1l of insulating material, here shown as supported by screws 12, which spool cai'- ries a winding of magnet wire 13 and has a vertical bore. Extending upwardly into this bore is an iron core 14 fastened to one end of the. cross-bar 15 of the rocking memberbt -posed along the said pivot axis B, and I insert into each of these peitorations the `stem ot' a pivot pin 16 which has a conical head bearing at its back against the outsidi` of the casing. Then I provide the rocking member with a pair of upwardly directed arms' 1T spaced by a distance greater than that between the tips of the projecting pivot pins 16. and provided with a pair ot alined perforations 18 in the said arms. In each of these pertorations 1S I socket the stem ot a pivot element 19 which has an enlarged head presenting a substantially cup-shaped recess' towards the conical head of one of the pivot pins 16.'

Operatively interposed between the lower end of the carbon pile and the bottoni plate or cross-bar 15 of the rocking member is a thrust member Q0 which desirably has conical ends adapted to atl'ord point harVV ings in opposed and conically cupped thrust. receiving elements associated respectively with a lower presser head Q5 engaging the carbon pile and with the said crosshar l.` For this purpose` I am here showing the lower eup-shaped thrust element. as the head ol' a bolt 2l which extends through a correspondingly disl'iosed [.ierioration 2Q in the iie y and the cross-bar 15 of the rocking cross-bar 15 and is secured in position by a lower nut 23. Then I am showing the upper and downwardly cupped thrust reoeiving element as an iron block 8 socketed in an insulating cup 24 which in turn is socketed in the said presser head 25. This presser head 25 is desirably secured lo the lowermost and l'rustro-carbon block 2G by a metal collar 27 spun over both of the said elements after the manner shown in Fig. 3, the said collar desirably also being iliade ot' iron. To receive the resulting upward thrust, I desirably flange the lower end or head 28 of terminal bolt 8 over the head of the upper carbon block 29.

lilith the parts thus arranged and the rocking member thus pivotally connected to the stationary casing 5, the thrust member and the carbon pile are disposed in tandem between the top 1 of the supporting member member and are held in position without requiring any auxiliary fastening elements. To vary the extent of the compression of the carbon pile, I dispose the thrust member 2O obliquely to the conipression axis (l of the carbon pile this being readily accomplished by loeating the axis of the thrust element. 2l at one side ot the said axis of compression, thereby effectively disposing the lever arm of the rocking member still more obliquely at the same side of the said axis, as shown diagrammatically in Fig. 7. When thus disposed, it will be obvious 'that the movement ot' the rocking member in a clockwise direction or one corresponding to a pull of the electromagnet on the core 1 will tend to aline the thrust member with the said compression axis, thereby decreasing the distance between the upper end of the carbon pile and the lower thrust elements 2 and causing a corresponding compression of the resistance, as also shown diagrammatically in rig. 7.

'To oppose a movement ohthe rocking member in its said compression-effecting direction, I interpose a tension spring 30 between the supporting member and the end ot' the cross bar 15 which is on the opposite side of the said anis of compression (and oru the pivot axis of the rocking member) `from the solenoid core 14. FThis spring 30 is secured at its upper end to a slide block 31. which bears against the downwardly directed end flange 3 of the supporting member so as to be kept by this flange from rotating. 'Threaded into this slide block 31 is a. screw 32 which extends rotatably through the top 1 of the supporting member and which has the upper surface of its head provided with a series of radial notches any one of which may be engaged by the downwardly directed end of a flat latehing spring so as to he locked against rotation. To simplify the construction, I desirably employ the ten mina] bolt 8 also. as the means for fastening the other end of the spring to the supporting member after the manner shown in Fig. 3. this latching spring being insulated from the stem ot' the said bolt by the insulating tube 9`and being interposed between a pair of insulating washers which insulate the spring both from the top 1 of the supporting member and from the lcircuit terminal 34 which is clamped under the nut 10.

To counterloalance the weight of the coro 14 as disposed at one end of vthe cross-arm 15 of the rocking member, I desirably pro* vide this rocking member'with portions disposed at opposite sides of the pivot axis of the rocking member from the said core. For this purpose, I am here showing each of the arms 17 as provided with an extension wing 35. The two wings extend considerably beyond the casing of the resistance lengthwise of the rocking member, so that I can also utilize them in varying the distance between the opposed arms 17 so as to adjust the distance between the pivot bearings 19. For this purpose, I am showing the wings 35 as provided with alined perforations 36. Extending 'through these perforations is a threaded rod 87 carrying pairs of nuts 38 adjacent to the opposed faces of the two arms 17. In assembling the appliance, these arms can initially be sprung apart so that the pivots 19 will readily clear the tips of the pi rot pins`24. Then the outer nuts 38 can be screwed up so as to draw the arms suliiciently towards each other to afford the desired delicate pivoting of the rocking member, after which the inner nuts S8 are screwed outwardly or 'the stem 37 so as to lock the arms in rigidly spaced relation.

To provide the desired circuit connection to the movable end orn the resistance (which is here illustrated as the lower end) l desirably employ a 'thin `and somewhat `flexible metal conductor 3f) which I am here showing as provided with a. perforated end clamped into a corresponding groove in the lower presser head 25. This has its other end clamped to the corresponding circuit terminal il()v by a bolt i1 which extends through a perforation in the downwardly directed end 3 of the supporting member, both the bolt, the flexible conductor 39 and the circuit vterminal 40 being insulated 'from the supporting part by insulation after the many ner shown in Fig. 3. "When thus employed, the flexible conductor 39 desirably has a perforation considerably larger than the diameter of the spring 30 so that the spring can extend freely through it.

-With the parts thus arranged. it will be evident that all o'l the circuit connections are insulated from the'metal parts which torni the supporting member` the rocking member and the thrust receiving portions. By maklll ing the casing 5, the lower presser head 23 and the thrust member as well as the rocle in member oit iron, these cooperate with the so enoid core Min aording a magnetic circuit in the form oi a loop extending through the bore of the magnet, thereby considerably increasing the efficiency ot the solenoid. By

' whole is subjected to jarring. Consequently,

my appliance is highly suitable for use under conditions in which jarring cannot be avoided, as for example upon automobiles as a voltage regulator for the battery charging circuits. However, li do not vvishto be limited to this particular employment of my invention, or to the use of its various novel 'features in connection with one another.

Neither do il wish to be limited to the particular details ot construction and arrangement above described. it being obvious that these might be varied in many ways without departing either from the spirit or my invention or from the appended claims. For example, instead ot employing the casin of the reslstance as the pivotal mounting tor one end oi the rocking member, ll may rovide the pressure-receiving top with an integral arm t2 extending alongside the resistance, as

shown in Fig. 8. So also, the mounting ol? the solenoid and of its core might be altered as shown in the same figure.

l claim as my invention l. ln a rheostat, a compressible resistance member having one end stationary, a roeking member pivoted on a stationary axis disposed between the ends oi the resi w member, a thrust member interposed between the rocking member and the other end ot the resistance member and disposed in oblique extension of the compression axis of the re- T tion with adjustable means for spacing the sistance member, and electromagnetic means for moving the rockingmember in one direction. l

2. A rheostat as per claimY 1, in combination with spring means for resisting the movement of the rocking member in the said direction.

3. A rheostat as per claim l, in `which the electromagnetic means include a stationsv solenoid and a movable core for the solenoi the core being mounted on the rocking member.

, 4. A rheostat comprising a pile of comprossible resistance elements. a stationary casing housing the pile and having a substantially closed end against which the pile can be compressed, a rocking member pivoted to the casing on an axis transversely inter- 'rocking member is pivoted on an anis transverse of the axis ot 'the pileand passing through the pile near the engagement oit the latter with .the thrust member,

6. A heostat4 as per claim 4r, in combination with means for insulating the pile from the thrust member. 1

7. A rheostat as per claim l, in which the rocking member has a pair of pivot arms at opposite sides of the said casing., in combination with adjustable means tor spacing the pivot arms.

8. ln a rheostat of the ty e having a thrust member and a compressi le resistance extending obliqueto each other and interposed in tandem between a stationary supporting member and a rocking member, a casing tor the resistance, and cooperating pivot members respectively carried by the casing and rocking member, the said pivot members comprising two pairs, one palr being mounted on opposite wall portions ot the casing, the rocking member having a pair ot arms disposed at opposite sides of the casing and respectively carrying the other two pivotv members.

9. lin a rheostat ot the type having a thrust member and a compressible resistance oblique to each other and interposed in tandem between a stationary supporting member and a rocking member, a casing for the resistance, a pair of arms upon the rocking member extending at opposite sides of the easing, and coo erating elements upon the said arms and the casing for pivotally connecting the rocking member to the casing, the arms being adapted to be flexed toward or away from each other.

i0. A rheostat as per claim 8, 'in combinasaid arms.

11. lin a rheostat of the typev having a thrust member and a compressible resistance interposed in tandem between a stationary supporting member and a rocking member, a casing for the resistance, the casing having lperiorations in opposed wall portions and the rocking member having perforations alining with the aforesaid perforations, and

tlf)

' Mil two relatively cooperating pairs oi pivot I members respectively socketed in the per iorations of the casing and the rocking member.

l2. lin a rheostat, a compressible resistance having oneend thereof stationary, a casing slidably housing the resistance, a rocking member pivoted to the casing on an airis transverse of the axis of compression of the resistance, a thrust member interposed between the other end of the resistance and the rocking member and extending at an oblique angleto the said axis of compression, an iron core mounted on one end of the rocking member, a solenoid into which the core extends, and means associated with the other end of the rockingmember for resisting the attraction of the core by the solenoid.

13. In a rheostat, a compressible resistance having one end thereof stationary, a rocking member pivoted on an axis `transverse of the axis of compression of the resistance, a thrust member interposed betweenv the other end of the resistancefandthe rocking member `and extending at an oblique angleto the said axis of compression, an iron core mounted on one end of the rocking member, anda solenoid into which the core extends, the rocking member having a weighted portion at its other end for counterbalancing the weight of the core. y

14. A rheostat as per claim 12, in which the casing is of iron, including an iron supporting member carrying the solenoid and the said casing; the thrust member and the rocking member being also of iron and cooperating With the core, the supporting member and the casing in forming a ma net-ic circuit extendingthrough the solenoid.

15. A rheostat as per claim 12, including a sup orting member carrying the solenoid and t e rocking member and against which the resistance is compressed, a sliding member mounted upon the supportng member for movement toward or away from the rocking member, and a tension spring interposed between the sliding member, and the rocking member, and normally latched means for moving the sliding member.

16. A rheostat as per claim 12, including a supporting member carrying the solenoid and the rocking member and against which .the resistance is compressed, a screw extending through the supporting member toward the rocking member, a sliding member in threaded engagement with the screw, and a tension spring interposed between the slidlng member and the rocking member, the supporting member havine" a portion slidably engaged by the slidlng member and preventin the l/at-ter :trom rotating.

17. A r eostat as per claim l2, including a supporting member carrying the solenoid and the rocking 4member and against which the resistance'is compressed, a pair of circuit terminals mounted on the supporting member, means associated with each terminal for insulating the same from the supporting member, one terminal being in conducting relation to the stationary end of the resistance, and a flexible conductor connecting the other terminal with the other end of the resistance.

Signed at St. Louis, Missouri., June 11, 1924.

HARRY B. MARSHALL. 

